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Kevin O'Connorf076a3e2008-02-25 22:25:15 -05001// 16bit code to access floppy drives.
2//
3// Copyright (C) 2008 Kevin O'Connor <kevin@koconnor.net>
4// Copyright (C) 2002 MandrakeSoft S.A.
5//
6// This file may be distributed under the terms of the GNU GPLv3 license.
7
8#include "types.h" // u8
9#include "disk.h" // DISK_RET_SUCCESS
10#include "config.h" // CONFIG_FLOPPY_SUPPORT
11#include "biosvar.h" // struct bregs
12#include "util.h" // irq_disable
13#include "cmos.h" // inb_cmos
14
15#define BX_FLOPPY_ON_CNT 37 /* 2 seconds */
16
Kevin O'Connor38fcbfe2008-02-25 22:30:47 -050017// XXX - //.org 0xefc7
18
Kevin O'Connorf076a3e2008-02-25 22:25:15 -050019// Since no provisions are made for multiple drive types, most
20// values in this table are ignored. I set parameters for 1.44M
21// floppy here
22char diskette_param_table[11] = {
23 0xAF,
24 0x02, // head load time 0000001, DMA used
25 0x25,
26 0x02,
27 18,
28 0x1B,
29 0xFF,
30 0x6C,
31 0xF6,
32 0x0F,
33 0x08,
34};
35
36// New diskette parameter table adding 3 parameters from IBM
37// Since no provisions are made for multiple drive types, most
38// values in this table are ignored. I set parameters for 1.44M
39// floppy here
40char diskette_param_table2[14] VISIBLE = {
41 0xAF,
42 0x02, // head load time 0000001, DMA used
43 0x25,
44 0x02,
45 18,
46 0x1B,
47 0xFF,
48 0x6C,
49 0xF6,
50 0x0F,
51 0x08,
52 79, // maximum track
53 0, // data transfer rate
54 4, // drive type in cmos
55};
56
57// Oddities:
58// Return codes vary greatly - AL not cleared consistenlty, BDA return
59// status not set consistently, sometimes panics.
60// Extra outb(0x000a, 0x02) in read?
61// Does not disable interrupts on failure paths.
62// numfloppies used before set in int_1308
63// int_1305 verifies track but doesn't use it?
64
65static inline void
66set_diskette_current_cyl(u8 drive, u8 cyl)
67{
68 if (drive)
69 SET_BDA(floppy_track1, cyl);
70 else
71 SET_BDA(floppy_track0, cyl);
72}
73
74static u16
75get_drive_type(u8 drive)
76{
77 // check CMOS to see if drive exists
78 u8 drive_type = inb_cmos(CMOS_FLOPPY_DRIVE_TYPE);
79 if (drive == 0)
80 drive_type >>= 4;
81 else
82 drive_type &= 0x0f;
83 return drive_type;
84}
85
86static u16
87floppy_media_known(u8 drive)
88{
89 if (!(GET_BDA(floppy_recalibration_status) & (1<<drive)))
90 return 0;
91 u8 v = GET_BDA(floppy_media_state[drive]);
92 if (!(v & FMS_MEDIA_DRIVE_ESTABLISHED))
93 return 0;
94 return 1;
95}
96
97static void
98floppy_reset_controller()
99{
100 // Reset controller
101 u8 val8 = inb(PORT_FD_DOR);
102 outb(val8 & ~0x04, PORT_FD_DOR);
103 outb(val8 | 0x04, PORT_FD_DOR);
104
105 // Wait for controller to come out of reset
106 while ((inb(PORT_FD_STATUS) & 0xc0) != 0x80)
107 ;
108}
109
110static void
111floppy_prepare_controller(u8 drive)
112{
113 CLEARBITS_BDA(floppy_recalibration_status, FRS_TIMEOUT);
114
115 // turn on motor of selected drive, DMA & int enabled, normal operation
116 u8 prev_reset = inb(PORT_FD_DOR) & 0x04;
117 u8 dor = 0x10;
118 if (drive)
119 dor = 0x20;
120 dor |= 0x0c;
121 dor |= drive;
122 outb(dor, PORT_FD_DOR);
123
124 // reset the disk motor timeout value of INT 08
125 SET_BDA(floppy_motor_counter, BX_FLOPPY_ON_CNT);
126
127 // wait for drive readiness
128 while ((inb(PORT_FD_STATUS) & 0xc0) != 0x80)
129 ;
130
131 if (prev_reset == 0) {
132 irq_enable();
133 u8 v;
134 do {
135 v = GET_BDA(floppy_recalibration_status);
136 } while ((v & FRS_TIMEOUT) == 0);
137 irq_disable();
138
139 v &= ~FRS_TIMEOUT;
140 SET_BDA(floppy_recalibration_status, v);
141 }
142}
143
144static u8
145floppy_pio(u8 *cmd, u8 cmdlen)
146{
147 floppy_prepare_controller(cmd[1] & 1);
148
149 // send command to controller
150 u8 i;
151 for (i=0; i<cmdlen; i++)
152 outb(cmd[i], PORT_FD_DATA);
153
154 irq_enable();
155 u8 v;
156 do {
157 if (!GET_BDA(floppy_motor_counter)) {
158 irq_disable();
159 floppy_reset_controller();
160 return DISK_RET_ETIMEOUT;
161 }
162 v = GET_BDA(floppy_recalibration_status);
163 } while (!(v & FRS_TIMEOUT));
164 irq_disable();
165
166 v &= ~FRS_TIMEOUT;
167 SET_BDA(floppy_recalibration_status, v);
168
169 if ((inb(PORT_FD_STATUS) & 0xc0) != 0xc0)
170 BX_PANIC("int13_diskette: ctrl not ready\n");
171
172 return 0;
173}
174
175static u8
176floppy_cmd(struct bregs *regs, u16 count, u8 *cmd, u8 cmdlen)
177{
178 // es:bx = pointer to where to place information from diskette
179 // port 04: DMA-1 base and current address, channel 2
180 // port 05: DMA-1 base and current count, channel 2
181 u16 page = regs->es >> 12; // upper 4 bits
182 u16 base_es = regs->es << 4; // lower 16bits contributed by ES
183 u16 base_address = base_es + regs->bx; // lower 16 bits of address
184 // contributed by ES:BX
185 if (base_address < base_es)
186 // in case of carry, adjust page by 1
187 page++;
188
189 // check for 64K boundary overrun
190 u16 last_addr = base_address + count;
191 if (last_addr < base_address)
192 return DISK_RET_EBOUNDARY;
193
194 u8 mode_register = 0x4a; // single mode, increment, autoinit disable,
195 if (cmd[0] == 0xe6)
196 // read
197 mode_register = 0x46;
198
199 DEBUGF("floppy dma c2");
200 outb(0x06, PORT_DMA1_MASK_REG);
201 outb(0x00, PORT_DMA1_CLEAR_FF_REG); // clear flip-flop
202 outb(base_address, PORT_DMA_ADDR_2);
203 outb(base_address>>8, PORT_DMA_ADDR_2);
204 outb(0x00, PORT_DMA1_CLEAR_FF_REG); // clear flip-flop
205 outb(count, PORT_DMA_CNT_2);
206 outb(count>>8, PORT_DMA_CNT_2);
207
208 // port 0b: DMA-1 Mode Register
209 // transfer type=write, channel 2
210 outb(mode_register, PORT_DMA1_MODE_REG);
211
212 // port 81: DMA-1 Page Register, channel 2
213 outb(page, PORT_DMA_PAGE_2);
214
215 outb(0x02, PORT_DMA1_MASK_REG); // unmask channel 2
216
217 u8 ret = floppy_pio(cmd, cmdlen);
218 if (ret)
219 return ret;
220
221 // read 7 return status bytes from controller
222 u8 i;
223 for (i=0; i<7; i++) {
224 u8 v = inb(PORT_FD_DATA);
225 cmd[i] = v;
226 SET_BDA(floppy_return_status[i], v);
227 }
228
229 return 0;
230}
231
232static void
233floppy_drive_recal(u8 drive)
234{
235 // send Recalibrate command (2 bytes) to controller
236 u8 data[12];
237 data[0] = 0x07; // 07: Recalibrate
238 data[1] = drive; // 0=drive0, 1=drive1
239 floppy_pio(data, 2);
240
241 SETBITS_BDA(floppy_recalibration_status, 1<<drive);
242 set_diskette_current_cyl(drive, 0);
243}
244
245static u16
246floppy_media_sense(u8 drive)
247{
248 u16 rv;
249 u8 config_data, media_state;
250
251 floppy_drive_recal(drive);
252
253 // for now cheat and get drive type from CMOS,
254 // assume media is same as drive type
255
256 // ** config_data **
257 // Bitfields for diskette media control:
258 // Bit(s) Description (Table M0028)
259 // 7-6 last data rate set by controller
260 // 00=500kbps, 01=300kbps, 10=250kbps, 11=1Mbps
261 // 5-4 last diskette drive step rate selected
262 // 00=0Ch, 01=0Dh, 10=0Eh, 11=0Ah
263 // 3-2 {data rate at start of operation}
264 // 1-0 reserved
265
266 // ** media_state **
267 // Bitfields for diskette drive media state:
268 // Bit(s) Description (Table M0030)
269 // 7-6 data rate
270 // 00=500kbps, 01=300kbps, 10=250kbps, 11=1Mbps
271 // 5 double stepping required (e.g. 360kB in 1.2MB)
272 // 4 media type established
273 // 3 drive capable of supporting 4MB media
274 // 2-0 on exit from BIOS, contains
275 // 000 trying 360kB in 360kB
276 // 001 trying 360kB in 1.2MB
277 // 010 trying 1.2MB in 1.2MB
278 // 011 360kB in 360kB established
279 // 100 360kB in 1.2MB established
280 // 101 1.2MB in 1.2MB established
281 // 110 reserved
282 // 111 all other formats/drives
283
284 switch (get_drive_type(drive)) {
285 case 1:
286 // 360K 5.25" drive
287 config_data = 0x00; // 0000 0000
288 media_state = 0x25; // 0010 0101
289 rv = 1;
290 break;
291 case 2:
292 // 1.2 MB 5.25" drive
293 config_data = 0x00; // 0000 0000
294 media_state = 0x25; // 0010 0101 // need double stepping??? (bit 5)
295 rv = 1;
296 break;
297 case 3:
298 // 720K 3.5" drive
299 config_data = 0x00; // 0000 0000 ???
300 media_state = 0x17; // 0001 0111
301 rv = 1;
302 break;
303 case 4:
304 // 1.44 MB 3.5" drive
305 config_data = 0x00; // 0000 0000
306 media_state = 0x17; // 0001 0111
307 rv = 1;
308 break;
309 case 5:
310 // 2.88 MB 3.5" drive
311 config_data = 0xCC; // 1100 1100
312 media_state = 0xD7; // 1101 0111
313 rv = 1;
314 break;
315 //
316 // Extended floppy size uses special cmos setting
317 case 6:
318 // 160k 5.25" drive
319 config_data = 0x00; // 0000 0000
320 media_state = 0x27; // 0010 0111
321 rv = 1;
322 break;
323 case 7:
324 // 180k 5.25" drive
325 config_data = 0x00; // 0000 0000
326 media_state = 0x27; // 0010 0111
327 rv = 1;
328 break;
329 case 8:
330 // 320k 5.25" drive
331 config_data = 0x00; // 0000 0000
332 media_state = 0x27; // 0010 0111
333 rv = 1;
334 break;
335 default:
336 // not recognized
337 config_data = 0x00; // 0000 0000
338 media_state = 0x00; // 0000 0000
339 rv = 0;
340 }
341
342 SET_BDA(floppy_last_data_rate, config_data);
343 SET_BDA(floppy_media_state[drive], media_state);
344 return rv;
345}
346
347static inline void
348floppy_ret(struct bregs *regs, u8 code)
349{
350 regs->ah = code;
351 SET_BDA(floppy_last_status, code);
352 set_cf(regs, code);
353}
354
355static inline void
356floppy_fail(struct bregs *regs, u8 code)
357{
358 regs->al = 0; // no sectors read
359 floppy_ret(regs, code);
360}
361
362static u16
363check_drive(struct bregs *regs, u8 drive)
364{
365 // see if drive exists
366 if (drive > 1 || !get_drive_type(drive)) {
367 floppy_fail(regs, DISK_RET_ETIMEOUT);
368 return 1;
369 }
370
371 // see if media in drive, and type is known
372 if (floppy_media_known(drive) == 0 && floppy_media_sense(drive) == 0) {
373 floppy_fail(regs, DISK_RET_EMEDIA);
374 return 1;
375 }
376 return 0;
377}
378
379// diskette controller reset
380static void
381floppy_1300(struct bregs *regs, u8 drive)
382{
383 if (drive > 1) {
384 floppy_ret(regs, DISK_RET_EPARAM);
385 return;
386 }
387 if (!get_drive_type(drive)) {
388 floppy_ret(regs, DISK_RET_ETIMEOUT);
389 return;
390 }
391 set_diskette_current_cyl(drive, 0); // current cylinder
392 floppy_ret(regs, DISK_RET_SUCCESS);
393}
394
395// Read Diskette Status
396static void
397floppy_1301(struct bregs *regs, u8 drive)
398{
399 u8 v = GET_BDA(floppy_last_status);
400 regs->ah = v;
401 set_cf(regs, v);
402}
403
404// Read Diskette Sectors
405static void
406floppy_1302(struct bregs *regs, u8 drive)
407{
408 if (check_drive(regs, drive))
409 return;
410
411 u8 num_sectors = regs->al;
412 u8 track = regs->ch;
413 u8 sector = regs->cl;
414 u8 head = regs->dh;
415
416 if (head > 1 || sector == 0 || num_sectors == 0
417 || track > 79 || num_sectors > 72) {
418 BX_INFO("int13_diskette: read/write/verify: parameter out of range\n");
419 floppy_fail(regs, DISK_RET_EPARAM);
420 return;
421 }
422
423 // send read-normal-data command (9 bytes) to controller
424 u8 data[12];
425 data[0] = 0xe6; // e6: read normal data
426 data[1] = (head << 2) | drive; // HD DR1 DR2
427 data[2] = track;
428 data[3] = head;
429 data[4] = sector;
430 data[5] = 2; // 512 byte sector size
431 data[6] = sector + num_sectors - 1; // last sector to read on track
432 data[7] = 0; // Gap length
433 data[8] = 0xff; // Gap length
434
435 u16 ret = floppy_cmd(regs, (num_sectors * 512) - 1, data, 9);
436 if (ret) {
437 floppy_fail(regs, ret);
438 return;
439 }
440
441 if (data[0] & 0xc0) {
442 floppy_fail(regs, DISK_RET_ECONTROLLER);
443 return;
444 }
445
446 // ??? should track be new val from return_status[3] ?
447 set_diskette_current_cyl(drive, track);
448 // AL = number of sectors read (same value as passed)
449 floppy_ret(regs, DISK_RET_SUCCESS);
450}
451
452// Write Diskette Sectors
453static void
454floppy_1303(struct bregs *regs, u8 drive)
455{
456 if (check_drive(regs, drive))
457 return;
458
459 u8 num_sectors = regs->al;
460 u8 track = regs->ch;
461 u8 sector = regs->cl;
462 u8 head = regs->dh;
463
464 if (head > 1 || sector == 0 || num_sectors == 0
465 || track > 79 || num_sectors > 72) {
466 BX_INFO("int13_diskette: read/write/verify: parameter out of range\n");
467 floppy_fail(regs, DISK_RET_EPARAM);
468 return;
469 }
470
471 // send write-normal-data command (9 bytes) to controller
472 u8 data[12];
473 data[0] = 0xc5; // c5: write normal data
474 data[1] = (head << 2) | drive; // HD DR1 DR2
475 data[2] = track;
476 data[3] = head;
477 data[4] = sector;
478 data[5] = 2; // 512 byte sector size
479 data[6] = sector + num_sectors - 1; // last sector to write on track
480 data[7] = 0; // Gap length
481 data[8] = 0xff; // Gap length
482
483 u8 ret = floppy_cmd(regs, (num_sectors * 512) - 1, data, 9);
484 if (ret) {
485 floppy_fail(regs, ret);
486 return;
487 }
488
489 if (data[0] & 0xc0) {
490 if (data[1] & 0x02) {
491 regs->ax = 0x0300;
492 set_cf(regs, 1);
493 return;
494 }
495 BX_PANIC("int13_diskette_function: read error\n");
496 }
497
498 // ??? should track be new val from return_status[3] ?
499 set_diskette_current_cyl(drive, track);
500 // AL = number of sectors read (same value as passed)
501 floppy_ret(regs, DISK_RET_SUCCESS);
502}
503
504// Verify Diskette Sectors
505static void
506floppy_1304(struct bregs *regs, u8 drive)
507{
508 if (check_drive(regs, drive))
509 return;
510
511 u8 num_sectors = regs->al;
512 u8 track = regs->ch;
513 u8 sector = regs->cl;
514 u8 head = regs->dh;
515
516 if (head > 1 || sector == 0 || num_sectors == 0
517 || track > 79 || num_sectors > 72) {
518 BX_INFO("int13_diskette: read/write/verify: parameter out of range\n");
519 floppy_fail(regs, DISK_RET_EPARAM);
520 return;
521 }
522
523 // ??? should track be new val from return_status[3] ?
524 set_diskette_current_cyl(drive, track);
525 // AL = number of sectors verified (same value as passed)
526 floppy_ret(regs, DISK_RET_SUCCESS);
527}
528
529// format diskette track
530static void
531floppy_1305(struct bregs *regs, u8 drive)
532{
533 DEBUGF("floppy f05\n");
534
535 if (check_drive(regs, drive))
536 return;
537
538 u8 num_sectors = regs->al;
539 u8 head = regs->dh;
540
541 if (head > 1 || num_sectors == 0 || num_sectors > 18) {
542 BX_INFO("int13_diskette: read/write/verify: parameter out of range\n");
543 floppy_fail(regs, DISK_RET_EPARAM);
544 return;
545 }
546
547 // send format-track command (6 bytes) to controller
548 u8 data[12];
549 data[0] = 0x4d; // 4d: format track
550 data[1] = (head << 2) | drive; // HD DR1 DR2
551 data[2] = 2; // 512 byte sector size
552 data[3] = num_sectors; // number of sectors per track
553 data[4] = 0; // Gap length
554 data[5] = 0xf6; // Fill byte
555
556 u8 ret = floppy_cmd(regs, (num_sectors * 4) - 1, data, 6);
557 if (ret) {
558 floppy_fail(regs, ret);
559 return;
560 }
561
562 if (data[0] & 0xc0) {
563 if (data[1] & 0x02) {
564 regs->ax = 0x0300;
565 set_cf(regs, 1);
566 return;
567 }
568 BX_PANIC("int13_diskette_function: read error\n");
569 }
570
571 set_diskette_current_cyl(drive, 0);
572 floppy_ret(regs, 0);
573}
574
575// read diskette drive parameters
576static void
577floppy_1308(struct bregs *regs, u8 drive)
578{
579 DEBUGF("floppy f08\n");
580
581 u8 drive_type = inb_cmos(CMOS_FLOPPY_DRIVE_TYPE);
582 u8 num_floppies = 0;
583 if (drive_type & 0xf0)
584 num_floppies++;
585 if (drive_type & 0x0f)
586 num_floppies++;
587
588 if (drive > 1) {
589 regs->ax = 0;
590 regs->bx = 0;
591 regs->cx = 0;
592 regs->dx = 0;
593 regs->es = 0;
594 regs->di = 0;
595 regs->dl = num_floppies;
596 set_cf(regs, 0);
597 return;
598 }
599
600 if (drive == 0)
601 drive_type >>= 4;
602 else
603 drive_type &= 0x0f;
604
605 regs->bh = 0;
606 regs->bl = drive_type;
607 regs->ah = 0;
608 regs->al = 0;
609 regs->dl = num_floppies;
610
611 switch (drive_type) {
612 case 0: // none
613 regs->cx = 0;
614 regs->dh = 0; // max head #
615 break;
616
617 case 1: // 360KB, 5.25"
618 regs->cx = 0x2709; // 40 tracks, 9 sectors
619 regs->dh = 1; // max head #
620 break;
621
622 case 2: // 1.2MB, 5.25"
623 regs->cx = 0x4f0f; // 80 tracks, 15 sectors
624 regs->dh = 1; // max head #
625 break;
626
627 case 3: // 720KB, 3.5"
628 regs->cx = 0x4f09; // 80 tracks, 9 sectors
629 regs->dh = 1; // max head #
630 break;
631
632 case 4: // 1.44MB, 3.5"
633 regs->cx = 0x4f12; // 80 tracks, 18 sectors
634 regs->dh = 1; // max head #
635 break;
636
637 case 5: // 2.88MB, 3.5"
638 regs->cx = 0x4f24; // 80 tracks, 36 sectors
639 regs->dh = 1; // max head #
640 break;
641
642 case 6: // 160k, 5.25"
643 regs->cx = 0x2708; // 40 tracks, 8 sectors
644 regs->dh = 0; // max head #
645 break;
646
647 case 7: // 180k, 5.25"
648 regs->cx = 0x2709; // 40 tracks, 9 sectors
649 regs->dh = 0; // max head #
650 break;
651
652 case 8: // 320k, 5.25"
653 regs->cx = 0x2708; // 40 tracks, 8 sectors
654 regs->dh = 1; // max head #
655 break;
656
657 default: // ?
658 BX_PANIC("floppy: int13: bad floppy type\n");
659 }
660
661 /* set es & di to point to 11 byte diskette param table in ROM */
662 regs->es = SEG_BIOS;
663 regs->di = (u16)diskette_param_table2;
664 /* disk status not changed upon success */
665}
666
667// read diskette drive type
668static void
669floppy_1315(struct bregs *regs, u8 drive)
670{
671 DEBUGF("floppy f15\n");
672 if (drive > 1) {
673 regs->ah = 0; // only 2 drives supported
674 // set_diskette_ret_status here ???
675 set_cf(regs, 1);
676 return;
677 }
678 u8 drive_type = get_drive_type(drive);
679
680 regs->ah = (drive_type != 0);
681 set_cf(regs, 0);
682}
683
684// get diskette change line status
685static void
686floppy_1316(struct bregs *regs, u8 drive)
687{
688 DEBUGF("floppy f16\n");
689 if (drive > 1) {
690 floppy_ret(regs, DISK_RET_EPARAM);
691 return;
692 }
693 floppy_ret(regs, DISK_RET_ECHANGED);
694}
695
696static void
697floppy_13XX(struct bregs *regs, u8 drive)
698{
699 BX_INFO("int13_diskette: unsupported AH=%02x\n", GET_AH());
700 floppy_ret(regs, DISK_RET_EPARAM);
701}
702
703void
704floppy_13(struct bregs *regs, u8 drive)
705{
706 if (CONFIG_FLOPPY_SUPPORT) {
707 switch (regs->ah) {
708 case 0x00: floppy_1300(regs, drive); break;
709 case 0x01: floppy_1301(regs, drive); break;
710 case 0x02: floppy_1302(regs, drive); break;
711 case 0x03: floppy_1303(regs, drive); break;
712 case 0x04: floppy_1304(regs, drive); break;
713 case 0x05: floppy_1305(regs, drive); break;
714 case 0x08: floppy_1308(regs, drive); break;
715 case 0x15: floppy_1315(regs, drive); break;
716 case 0x16: floppy_1316(regs, drive); break;
717 default: floppy_13XX(regs, drive); break;
718 }
719 } else {
720 switch (regs->ah) {
721 case 0x01: floppy_1301(regs, drive); break;
722 default: floppy_13XX(regs, drive); break;
723 }
724 }
725}
726
727// INT 0Eh Diskette Hardware ISR Entry Point
728void VISIBLE
729handle_0e(struct bregs *regs)
730{
Kevin O'Connor4b60c002008-02-25 22:29:55 -0500731 //debug_enter(regs);
Kevin O'Connorf076a3e2008-02-25 22:25:15 -0500732 if ((inb(PORT_FD_STATUS) & 0xc0) != 0xc0) {
733 outb(0x08, PORT_FD_DATA); // sense interrupt status
734 while ((inb(PORT_FD_STATUS) & 0xc0) != 0xc0)
735 ;
736 do {
737 inb(PORT_FD_DATA);
738 } while ((inb(PORT_FD_STATUS) & 0xc0) == 0xc0);
739 }
740 eoi_master_pic();
741 // diskette interrupt has occurred
742 SETBITS_BDA(floppy_recalibration_status, FRS_TIMEOUT);
743}
744
745// Called from int08 handler.
746void
747floppy_tick()
748{
749 // time to turn off drive(s)?
750 u8 fcount = GET_BDA(floppy_motor_counter);
751 if (fcount) {
752 fcount--;
753 SET_BDA(floppy_motor_counter, fcount);
754 if (fcount == 0)
755 // turn motor(s) off
756 outb(inb(PORT_FD_DOR) & 0xcf, PORT_FD_DOR);
757 }
758}